Bug 509046 - xfreerdp "multimon" option gives corrupted visuals when direct scanout is enabled in Plasma Wayland
Summary: xfreerdp "multimon" option gives corrupted visuals when direct scanout is ena...
Status: REPORTED
Alias: None
Product: kwin
Classification: Plasma
Component: xwayland (other bugs)
Version First Reported In: 6.4.4
Platform: Arch Linux Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2025-09-03 01:01 UTC by ottersaregrt
Modified: 2025-09-03 01:01 UTC (History)
0 users

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Description ottersaregrt 2025-09-03 01:01:15 UTC 
SUMMARY
Using the "multimon" option in xfreerdp results in flickering and corrupted visuals. However, disabling direct scanout by adding KWIN_DRM_NO_DIRECT_SCANOUT=1 to environment variables fixes this issue.

This seems dependent on the monitors used. A setup with two 4k monitors and QHD ultrawide results in this bug appearing, but another setup using a QHD ultrawide and a normal QHD monitor works without needing to disable direct scanout.

Bug report in xfreerdp: https://github.com/FreeRDP/FreeRDP/issues/10098

STEPS TO REPRODUCE
1. Connect to a xfreerdp session using /multimon with multiple monitors

OBSERVED RESULT
Visuals appear to flicker and are corrupted on each monitor as the mouse is moved.

EXPECTED RESULT
Visuals should not be corrupted.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Arch 6.16.4
KDE Plasma Version: 6.4.4
KDE Frameworks Version: 6.17.0
Qt Version: 6.9.1

ADDITIONAL INFORMATION